Antioxidases play an important role in prevention of oxidative stress. Oxidative stress is a state of imbalance between generation of Reactive Oxygen Species like hydroxyl and superoxide radical, and the level of antioxidant defense system. Antioxidases prevent damage of biopolymers including nucleic acids, proteins, polyunsaturated fatty acids and carbohydrates caused by ROS. Further, antioxidants are believed to be important in the prevention of many diseases such as cardiovascular disease, diabetes, liver diseases and cancer. In 1960Âs Green revolution in India has witnessed a jump in agricultural production with the introduction of high yielding varieties of various crops and by following intensive cultivation practices with the use of fertilizers, pesticides and other inputs. The intensive use of inputs has not only polluted the soil, water and the environment causing their slow degradation but also affected the human beings due to the presence of insecticide and pesticide residues in food produce. The use of organic manures like farmyard manure and vermicompost improves physical, chemical and biological properties of the soil. It also sustains biological production, provides safe and nutritious food and phytochemicals from food crops and medicinal plants respectively. Therefore, the present investigation was aimed to study the effect of farmyard manure and vermicompost and the comparison with inorganic fertilizer on the level of antioxidases namely peroxidase and catalase of two selected medicinal plants namelyCinnamomum verum and Acorus calamus. The manural potential of three manures: inorganic fertilizers, farmyard manure and vermicompost on enzyme activity was evaluated at different time intervals (25, 50 and 75 days after planting). Our results revealed that the level (p<0.05) of peroxidase and catalase were found to be significantly higher in vermicompost applied plants when compared to control and other treatments.